Avitinib Maleate

本文总结具有代表性的共价蛋白激酶抑制剂（CKIs）所采用的主要药物化学策略，这些CKIs根据半胱氨酸在激酶的七个主要区域中的位置进行分类：前部区域、富含甘氨酸的环（P-loop）、铰链区域、DFG区域、激活环（A-loop）、催化环（C-loop）和远端环。图1、CKI和常用弹头的发现策略共价激酶抑制动力学共价抑制被认为是一个两步过程，第一步是非共价结合过程，第二步是共价键形成过程（图2）。由于亲电弹头的发展能够经历一个正向共价反应，然后以生物学相关的速率进行反向消除步骤，CKIs可以分为两类，称为“不可逆共价”和“可逆共价”抑制剂。可逆共价抑制剂仍然与激酶保持共价连接，只要它们通过与靶标的其他非共价相互作用来稳定，提供延长的作用时间（停留时间）和高选择性。图2、“不可逆共价”和“可逆共价”抑制剂的动力学相互作用共价激酶抑制剂的发现策略CKIs发现的两种主要策略是经验筛选和基于结构的药物设计，如图3所示。筛选策略包括表型筛选和高通量筛选(HTS)聚焦共价激酶抑制剂或片段。这些方法与发现非共价激酶抑制剂时通常采用的方法相似。当生物学靶点不可用时，表型筛选可能是一种有用的方法，而当缺乏已知的激酶靶点可逆抑制剂时，聚焦共价激酶抑制剂或片段的HTS是合适的。一旦初步确定，蛋白质x射线晶体学和质谱研究最初用于确定共价结合的目标残基。然后采用药物化学方法来优化激酶结合亲和力和激酶组选择性以及主要候选药物的类药物性质。发现共价抑制剂的一种常见可行策略是利用基于结构的设计在可逆抑制剂上添加亲电团，以确定可逆抑制剂的最合适的官能化位置。此外，各种具有靶向半胱氨酸残基能力的不可逆和可逆共价弹头，如α、β-不饱和酰胺及其衍生物等，已被开发出来，为设计靶向共价和可逆共价抑制剂提供了许多选择。同时，计算机辅助的共价对接为快速发现CKIs提供了一种有用的方法。图3、CKI和常用弹头的发现策略具有代表性的共价激酶抑制剂虽然相当多的激酶在ATP位点有可接近的半胱氨酸，但只有一小部分具有共价配体的激酶被鉴定出来。因此，为了设计CKI，了解哪些半胱氨酸是可接近的，并且会与弹头发生反应是很重要的。Winssinger研究小组首次对活性构象、非活性“C-helix out”构象和非活性“DFG-out”构象中激酶的目标半胱氨酸位置进行了系统分析。Gray小组报告了ATP结合位点上可用的半胱氨酸位置，并将它们分为五个主要组：铰链区、守门员区、P-loop、A-loop（包括DFG区）和顶区。Bourne研究小组还通过使用功能位点相互作用指纹(Fs-IFP)和密度泛函数理论(DFT)计算，确定了容易获得的半胱氨酸的前五个。这些半胱氨酸是目前已知的95%的共价激酶抑制剂的靶标，它们位于DFG区周围的前部区域、P-loop、口袋顶部、C-loop和A-loop。我们总结了这些具有代表性的激酶（图4），详细介绍了半胱氨酸在前部区域、P-loop、铰链区、DFG区、A-loop、C-loop和远端环的位置，这些位置已被CKIs成功确认和靶向。图4、共价抑制剂靶向的代表性激酶的关键半胱氨酸残基的位置1）位于前部区域的半胱氨酸前部区域位于ATP结合位点的边缘，因此在这个位置的半胱氨酸可能有足够的开放空间来结合能够形成共价键的各种弹头。在前区含有半胱氨酸的激酶包括EGFR、ERBB2 (HER2)、ERBB4 (HER4)、BTK、JAK3、BLK、MKK7、TEC家族激酶（BMX、TEC、ITK和TXK）、EphB3和脂质激酶PI3Kα。7个获批的CKI均针对该区域的半胱氨酸，afatinib、dacomitinib和neratinib是二代靶向EGFR/HER2的CKIs（图5）；还有代表性的第三代突变型EGFR选择性CKI osimertinib和olmutinib以及临床候选药物nazartinib和avitinib（图6）。图5、获批的第二代EGFR/HER2抑制剂的发现图6、代表性的第三代突变型EGFR选择性共价激酶抑制剂克服EGFRT790M获得耐药性2）位于P-Loop的半胱氨酸P-Loop位于激酶结构域的C端，并以高度的灵活性包裹在ATP结合口袋上。靶向P-Loop中半胱氨酸的FGFR1−4、SRC和FAK的共价抑制剂被不断开发。成纤维细胞生长因子受体(FGFR)家族由四个高度保守的功能成员（FGFR1−4）组成，被认为是抗癌药物开发的有前途的分子靶点，靶向半胱氨酸开发了几种共价FGFR1−4抑制剂（图7），其中TAS-120（futibatinib）目前正在进行II期临床试验，用于治疗含有FGFR异常的晚期转移性实体瘤。非受体酪氨酸激酶SRC含有一个P-Loop半胱氨酸（Cys280），其相对位置与FGFR1的Cys488相同，这为设计具有更高效力和选择性的共价SRC抑制剂奠定了基础。研究者以混杂共价抑制剂SM1-71为起点，设计了一系列基于二氨基嘧啶的共价SRC选择性抑制剂（图8）。Focal adhesion kinase（FAK）在该激酶的P-Loop中也含有半胱氨酸残基，该半胱氨酸的相对位置与FGFR1的Cys488不同，它位于更靠近ATP结合位点的位置。研究者基于可逆抑制剂TAE266的首个不可逆FAK抑制剂的结构设计见图9。图7、代表性共价泛FGFR抑制剂图8、以混杂共价抑制剂SM1-71为起点设计共价SRC选择性抑制剂图9、共价FAK抑制剂29b和29是由可逆性抑制剂29a设计的3）位于铰链区的半胱氨酸铰链区位于激酶结构域的中间，位于N端和C端之间，是ATP结合口袋的一部分，已知与许多激酶抑制剂形成关键的氢键。通过靶向铰链区的半胱氨酸设计了FGFR4和FLT3共价抑制剂。除了在P-Loop中发现的保守半胱氨酸(Cys477)外，FGFR4在位于铰链区的激酶结构域中含有第二个半胱氨酸。Cys552在四种FGFR亚型中是独一无二的，并提供共价结合位点，使FGFR4抑制剂的发展具有异构体选择性。Fms样酪氨酸激酶3 (FLT3)的激活突变被认为是与急性髓性白血病(AML)预后不良相关的最常见的遗传改变。几种可逆的FLT3抑制剂已经开发出来，并在临床研究中证明了有效性。然而，对这些药物的临床获得性耐药总是出现，导致AML治疗的总体结果不佳。在FLT3的铰链区存在半胱氨酸(Cys695)，位于C末端，为开发具有克服临床耐药潜力的不可逆FLT3抑制剂提供机会。最近，FF-10101被报道为FLT3的不可逆抑制剂，对FLT3WT和FLT3D835Y具有较强的活性。图10、FF-10101的化学结构及其与FLT3的共价结合模式4）位于DFG区域的半胱氨酸大约10%的激酶在DFG基序附近有半胱氨酸残基。已报道的针对该区域半胱氨酸的抑制剂处于发现和表征的早期阶段。细胞外信号调节蛋白激酶1/2（ERK1/2）位于丝裂原活化蛋白激酶（MAPK）通路的出口，被认为是多种人类癌症中有吸引力的药物靶点。许多可逆的ERK1/2抑制剂已经公开，其中一些已经进入临床评估。ERK1/2在DFG区域的开始处含有半胱氨酸，为设计共价抑制剂提供了可能的靶点。真菌聚酮天然产物hypothemycin及其类似物是首次报道的ERK1/2的非选择性不可逆抑制剂。这些衍生物在大环内酯类顺式烯酮部分和DFG区域的半胱氨酸之间形成共价键。新型共价ERK1/2抑制剂的设计遵循了在可逆ERK1/2抑制剂支架的合适位置加入共价部位以与目标半胱氨酸形成共价键的策略。在此方法的指导下，阿斯利康基于可逆的内部筛选，开发了一系列基于氨基嘧啶的共价ERK1/2抑制剂（图11）。除了在ATP结合域的铰链区域有一个可靶向的半胱氨酸外，FLT3在DFG基序之前还含有一个高度保守的半胱氨酸(Cys828)。研究者报道了一种共价FLT3抑制剂36，该抑制剂靶向Cys828（图12）。转化生长因子-ß-活化激酶1（TAK1）属于MAPK激酶（MAP3K）家族，被认为是治疗癌症和免疫疾病的潜在治疗靶点。化合物37a在激酶抑制剂文库的kinome分析中被表征为有效的可逆TAK1抑制剂，它含有丙烯酰胺弹头。从37a和WZ4002开始的共价TAK1抑制剂37和38的发现（图13）。图11、从可逆ERK1/2抑制剂35a和35b开始设计CC-90003和35d图12、从虚拟文库中发现一种共价FLT3抑制剂36图13、从37a和WZ4002开始的共价TAK1抑制剂37和38的发现5）位于A-Loop的半胱氨酸丝氨酸/苏氨酸激酶AKT（蛋白激酶B/PKB）是PI3K/ AKT/mTOR信号通路的关键介质，在细胞增殖、存活、迁移和运动中起关键作用。AKT信号转导的异常激活与多种恶性肿瘤有关许多研究人员都在努力开发小分子AKT抑制剂，包括ATP竞争抑制剂和变构抑制剂。Borussertib是一种一流的共价变构AKT抑制剂（图30）。图14、共价变构AKT抑制剂borussertib及其衍生物6）位于C-Loop的半胱氨酸只有肥大细胞/干细胞生长因子受体（SCFR/c-KIT）和血小板衍生生长因子受体α（PDGFRα）报道针对激酶结构域C-Loop半胱氨酸的共价抑制剂。采用imatinib (40a)，用反应性α-氯乙酰胺弹头取代甲基哌嗪基团，提供共价c-KIT/PDGFRα抑制剂40（图15）。图14、从imatinib40a开始的共价c-KIT/PDGFRα抑制剂40的发现7）位于远端环的半胱氨酸周期蛋白依赖性激酶7（CDK7）的C端延伸包含一个保守性较差的非催化半胱氨酸（这里定义为远端环中的半胱氨酸），这在20个CDKs家族成员中是独一无二的。这种半胱氨酸(Cys312)为开发共价cdk7选择性抑制剂提供了一个潜在的靶点。首次报道的共价CDK7抑制剂THZ1是通过筛选ATP位点导向的激酶抑制剂文库发现的。THZ1含有一个苯基氨基嘧啶支架，它带有一个靶向CDK7的Cys312的丙烯酰胺片段（图33A）。进一步优化THZ1得到选择性共价CDK12/13抑制剂THZ531，THZ531与CDK12-cyclin K的共晶结构显示，THZ531与CDK12 C端延伸的Cys1039共价结合（图33B）。图14、(A)共价CDK7抑制剂42及其与CDK7的结合模式。(B)共价CDK12/13抑制剂43及其与CDK12-cyclin K的结合模式。小结CKIs的智能化设计将是未来发展的一个方向。化学信息学工具和算法可用于在已知的可逆抑制剂上自动添加各种弹头和连接体，从而扩大CKIs的化学空间，实现CKIs的大规模共价虚拟筛选和结构多样化。对激酶生物学和结构生物学的进一步了解以及这些新的药物设计技术将极大地促进新激酶的发现。参考文献：[1]Discovery of Cysteine-targeting Covalent Protein Kinase Inhibitors. J Med Chem. 2022 Jan 13;65(1):58-83.服务： 本公众号免费接受科研团队/单位的研究进展、研发故事等非商业/非盈利目的投稿，及免费发布科研团队的招聘广告等，欢迎后台联系。声明：发表/转载本文仅仅是出于传播信息的需要，并不意味着代表本公众号观点或证实其内容的真实性。据此内容作出的任何判断，后果自负。若有侵权，告知必删！长按关注本公众号   粉丝群/投稿/授权/广告等请联系公众号助手 觉得本文好看，请点这里↓

Abivertinib is a novel Bruton’s tyrosine kinase (BTK) inhibitor that irreversibly targets BTK. BTK inhibitors are a large category in cancer treatment, with multiple indications and generating over $10.6 billion per year revenue in 2022. In this phase IIa study conducted in China, a total of 27 R/R MZL patients treated with Abivertinib were assessed and the overall response rate (ORR) was 59.3 % (16/27 patients) and among them, 3 patients had complete responses (CR) with a CR rate of 11.1% (3/27patients) and disease control rate (DCR) was 92.6%. To date, progression free survival (PFS) and duration of response (DOR) have not been reached. Sorrento has communicated with the China Health Authority (National Medical Products Administration or NMPA) regarding the design of a pivotal phase III registration study of R/R MZL in China. SAN DIEGO, July 05, 2023 (GLOBE NEWSWIRE) -- Sorrento Therapeutics, Inc. (OTC: SRNEQ) today announced positive results from a China phase IIa study of Abivertinib on R/R MZL and its plan for a pivotal study. Abivertinib is a pyrrolopyrimidine-based, mutant EGFR and BTK dual inhibitor with potential across multiple indications. BTK inhibitors are a large category in cancer treatment, with multiple indications and generating over $10.6 billion per year revenue in 2022.(1) Abivertinib inhibits BTK with IC50 value of 0.4 nM. Previously, a positive phase Ib study result of Abivertinib on B cell lymphoma was reported.(2) The phase IIa study on R/R MZL, a rare type of B cell lymphoma, was conducted in China in 27 R/R MZL patients. Abivertinib showed significant treatment benefits in 27 patients who were relapsed or refractory after multiple lines of treatment with an ORR of 59.3% (11.1% CR and 48.2% partial responses). This ORR is higher than the ORR of Ibrutinib (46%), which was first approved for the treatment of R/R MZL.(3) The DCR was 92.6% and to date, both PFS and DOR have not been reached. In the phase IIa study, Abivertinib was well-tolerated, and no severe bleeding, arrhythmia (atrial fibrillation/flutter) or hypertension were seen in these Abivertinib-treated patients. Given these early results, Abivertinib has a promising safety and efficacy pro date, which has the potential for it to be preferable to the approved drug Ibrutinib.(3) Sorrento has communicated with the NMPA, and a consensus has been reached for a pivotal phase III registration study for the treatment of R/R MZL. The pivotal study will be a multicenter phase III study to assess the efficacy and safety of Abivertinib for treatment of relapsed/refractory marginal zone lymphoma. Sorrento will continue communicating with the NMPA to finalize the phase III protocol. “We are very encouraged by the significant positive results of Abivertinib for the treatment of R/R MZL, which would be a second indication of Abivertinib for cancer treatment in addition to the potential treatment of resistant EGFR mutant positive non-small cell lung cancer,” said Dr. Henry Ji, Ph.D., Chairman and CEO of Sorrento. About Sorrento Therapeutics, Inc. Sorrento is a clinical and commercial stage biopharmaceutical company developing new therapies to treat cancer, pain (non-opioid treatments), autoimmune disease, and COVID-19. Sorrento's multimodal, multipronged approach to fighting cancer is made possible by its extensive immuno-oncology platforms, including key assets such as next-generation tyrosine kinase inhibitors (“TKIs”), fully human antibodies (“G-MAB™ library”), immuno-cellular therapies (“DAR-T™”), antibody-drug conjugates (“ADCs”), and oncolytic virus (“Seprehvec™”). Sorrento is also developing potential antiviral therapies and vaccines against coronaviruses, including STI-1558 and COVI-MSC™, and diagnostic test solutions, including COVIMARK™. Sorrento's commitment to life-enhancing therapies for patients is also demonstrated by our effort to advance a TRPV1 agonist, non-opioid pain management small molecule, resiniferatoxin (“RTX”), and SP-102 (10 mg, dexamethasone sodium phosphate viscous gel) (SEMDEXA™), a novel, viscous gel formulation of a widely used corticosteroid for epidural injections to treat lumbosacral radicular pain, or sciatica, and to commercialize ZTlido® (lidocaine topical system) 1.8% for the treatment of postherpetic neuralgia (PHN). RTX has been cleared for a phase II trial for intractable pain associated with cancer and a phase II trial in osteoarthritis patients. Positive final results from the phase III Pivotal Trial C.L.E.A.R. Program for SEMDEXA™, its novel, non-opioid product for the treatment of lumbosacral radicular pain (sciatica), were announced in March 2022. ZTlido® was approved by the FDA on February 28, 2018. For more information visit Forward-Looking Statements This press release and any statements made for and during any presentation or meeting contain forward-looking statements related to Sorrento Therapeutics, Inc., under the safe harbor provisions of Section 21E of the Private Securities Litigation Reform Act of 1995 and subject to risks and uncertainties that could cause actual results to differ materially from those projected. Forward-looking statements include statements regarding Sorrento's products, technologies and prospects, Sorrento's plans and expectations regarding a pivotal registration study for the treatment of R/R MZL in China and its communications with the NMPA regarding the design of a pivotal phase III registration study for R/R MZL in China, Abivertinib’s potential to provide significant treatment benefits, Abivertinib’s promising safety and efficacy pro Abivertinib’s potential to be a preferable choice to the approved drug Ibrutinib. Risks and uncertainties that could cause our actual results to differ materially and adversely from those expressed in our forward-looking statements, include, but are not limited to: risks related to Sorrento's technologies and prospects, including, but not limited to risks related to safety and efficacy of Abivertinib and seeking regulatory approval for Abivertinib; clinical development risks, including risks in the progress, timing, cost, and results of clinical trials and product development programs; risk of difficulties or delays in obtaining regulatory approvals; risks that clinical study results may not meet any or all endpoints of a clinical study and that any data generated from such studies may not support a regulatory submission or approval; risks that prior test, study and trial results, including those for Abivertinib, may not be replicated in continuing or future studies and trials; risks of manufacturing and supplying drug product; risks related to leveraging the expertise of its employees, subsidiaries, affiliates and partners to assist Sorrento in the execution of its product candidates’ strategies; risks relating to the voluntary proceedings under Chapter 11 in the Bankruptcy Court (the "Chapter 11 Cases"), Sorrento's ability to continue operating in the ordinary course while the Chapter 11 Cases are pending, the timing and outcome of the Chapter 11 Cases, Sorrento's ability to obtain timely approval by the Bankruptcy Court of the motions filed in the Chapter 11 Cases, employee attrition and Sorrento's ability to retain senior management and other key personnel due to the distractions and uncertainties of the Chapter 11 Cases, Sorrento's ability to maintain relationships with suppliers, customers, employees and other third parties and regulatory authorities as a result of the Chapter 11 Cases, the Bankruptcy Court's rulings in the Chapter 11 Cases, the length of time that Sorrento will operate under Chapter 11 protection and the continued availability to Sorrento of operating capital during the pendency of the Chapter 11 Cases, risks associated with any third party motions in the Chapter 11 Cases, increased administrative and legal costs related to the chapter 11 process, exposure to potential litigation and inherent risks involved in a bankruptcy process, the potential adverse effects of the Chapter 11 Cases on Sorrento's liquidity or results of operations, or Sorrento's ability to timely periodic reports or meet periodic reporting requirements with the SEC; and other risks that are described in Sorrento's most recent periodic reports filed with the Securities and Exchange Commission, including Sorrento's Annual Report on Form 10-K for the year ended December 31, 2022 and subsequent Quarterly Reports on Form 10-Q filed with the Securities and Exchange Commission, including the risk factors set forth in those filings. Investors are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date of this release, and we undertake no obligation to update any forward-looking statement in this press release except as required by law. Media and Investor Relations Contact: Brian Cooley Email: mediarelations@sorrentotherapeutics.com Sorrento® and the Sorrento logo are registered trademarks of Sorrento Therapeutics, Inc. G-MAB™, DAR-T™, Seprehvec™, SOFUSA™, COVISHIELD™, COVIDROPS™, COVI-MSC™, COVIMARK™, Fujovee™ and Ovydso™ are trademarks of Sorrento Therapeutics, Inc. SEMDEXA™ (SP-102) is a trademark of Semnur Pharmaceuticals, Inc. A proprietary name review by the FDA is planned. ZTlido® is a registered trademark owned by Scilex Pharmaceuticals Inc. All other trademarks are the property of their respective owners. ©2023 Sorrento Therapeutics, Inc. All Rights Reserved. References: (1). Marketwatch; Press Release: Global Bruton's Tyrosine Kinase (BTK) Inhibitors Market [2023] | New Report Anticipates Industry to Surpass USD 25770 Million in Revenue by 2030, 4 May 2023 (2). Yang M., Qian J., Huang J., and etc., A phase 1 study of the BTK inhibitor abivertinib (AC0010) in patients with relapsed or refractory B-cell lymphoma, EHA Library, 06/14/2019; 266315, PF515 (3). Ibrutinib label,